This invention relates to optical-to-electrical and electrical-to-optical modules and more particularly to optical mounting features in such modules.
In optical-to-electrical and electrical-to-optical (hereinafter xe2x80x9coptoelectricxe2x80x9d) modules used in the various communications fields, one of the most difficult problems that must be solved is the provision of adequate, inexpensive optical elements and the alignment of these elements. Providing this efficient fabrication and alignment requires very precise assembly procedures. Here it will be understood by those skilled in the art that the term xe2x80x9clightxe2x80x9d, as used throughout this disclosure, is a generic term which includes any electromagnetic radiation that can be modulated and transmitted by optical fibers or other optical transmission lines (which at the present time is generally in the infrared range).
Much of the optoelectric module fabrication difficulty and expense is due to mounting and shielding difficulties of optical components, such as lasers, light emitting diodes, photodiodes, etc. Generally, there are two types of lasers that are used in optoelectric modules, edge emitting lasers and surface emitting lasers. Edge emitting lasers emit light in a path parallel to the mounting surface while surface emitting lasers emit light perpendicular to the mounting surface. The light from either of the lasers must then be directed into an optical fiber for transmission to a remotely located light receiver (i.e., a photodiode or the like). Lens systems are used at both ends of the optical fiber to direct light from a light generating component into the optical fiber and to direct light from the optical fiber onto a light sensing component.
The apparatus used to mount the optical components and the lens systems can have a substantial effect on the construction of the optical systems and the assembly procedures for the optical systems. Also, the mounting structure for the optical components and the lens system must be very rugged and stable so that alignment is not disturbed by use or temperature changes. Further, the entire module must be shielded from external signals and the like and to prevent radiation to other external devices or modules, (e.g., electromagnetic interference (EMI)).
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object the present invention to provide new and improved optical component and optical element mounting and alignment apparatus.
Another object of the present invention is to provide new and improved optical component and optical element mounting and alignment apparatus which is rugged and stable.
Another object of the present invention is to provide new and improved optical component and optical element mounting and alignment apparatus which is shielded to prevent radiation into and/or out of the module.
And another object of the present invention is to provide new and improved optical component and optical element mounting and alignment apparatus which improve the fabrication efficiency and manufacturing capabilities of optoelectric modules.
Still another object of the present invention, is to provide new and improved optical component and optical element mounting and alignment apparatus which allows the use of a variety of optical components and component materials.
Briefly, to achieve the desired objects of the present invention in accordance with a preferred embodiment thereof, provided is an optoelectric module including a cylindrical ferrule defining an optical axis and having a first end constructed to receive an optical fiber aligned along the optical axis and a second end. An optical element is engaged in the cylindrical ferrule between the first end and the second end. The optical element includes a lens positioned to convey light along the optical axis. A base is affixed adjacent the second end of the cylindrical ferrule so as to close the second end. An optical component is mounted on the base within the cylindrical ferrule so that light conveyed along the optical axis is directed through the lens of the optical element along the optical axis from the optical component to the optical fiber or from the optical fiber to the optical component. Either a laser driver or an amplifier is mounted on the base and electrically connected to the optical component by either electrical traces on a surface of the base, vias through at least a portion of the base, or flex leads mounted at least partially on the base. External connections are made to the laser driver or the amplifier by either electrical traces on a surface of the base, vias through at least a portion of the base, or flex leads mounted at least partially on the base.